To put the radiation dose in perspective: That is less exposure than the passengers/crew would get from a return flight Sydney to London.
Tell you what X-Class,
you go overnight into NRT and operate. Tell us all how the Iodine 131 and Caesium 137 tastes.....
There is NO safe maximum level of exposure for man made ionising radiation.. it might also be a small dose, but for how long? Iodine 131 has a half life of around 8 days, Caesium 137, about 30 years....
The J* crew have every right to refuse to overnight into NRT.
The situation at Fukushima cannot be underestimated. There are FOUR nuclear reactors there, 2 with severe cooling problems and power problems supplying the cooling system pumps.
Having read that they are having serious trouble trying the keep the core submerged in water and that some of the fuel is exposed to the air, would give me more than passing warm fuzzies of concern.
Tokyo is 200 km away to the south and there are reports that the wind is expected to change direction to a Northerly, blowing any radionuclides towards Tokyo. The French Embassy has also recommended that their nationals leave the northern Tokyo area as the situation at Fukushima is highly unpredictable.
But it's alright, because according to J* management, it's completely safe.
(Things to think about if your overnighting in NRT and the fallout heads your way...
Avoid Fresh milk. Any milk produced around the fall out area may contain Iodine 131. Actually make that any dairy...
Consider taking Iodine tablets, talk to a GP first. By taking normal iodine tablets, this protects your thyroid from taking up the radioactive Iodine 131 isotope, which decays giving a beta particle, hence giving off beta radiation.
Take off your outer layer of clothing before entering buildings and leave at the front door if in a fall out area. Cover your mouth and nose while outside with anything that will lower the amount of dust you breath in
Canned goods are probably the best and safest to eat, as is any bottled water.
)
Good Luck!
edited to add.. any dairy... be safe kiddies!